Major optimization, rewrite to avoid deep recursion if possible.

[SXSI/xpathcomp.git] / results.c

diff --git a/results.c b/results.c
index 7570e5a..4e7b4ec 100644 (file)
--- a/results.c
+++ b/results.c
@@ -29,8 +29,8 @@ results createResults (int n)
 \r
     R.n = 2*n-1;\r
     R.lgn = lg(n);\r
-    fprintf(stderr,"Size of the result set : %i elements, %li kB\n", n,\r
-           (((R.n+W-1)/W)*sizeof(int)/1024));\r
+    //fprintf(stderr,"Size of the result set : %i elements, %li kB\n", n,\r
+    //(((R.n+W-1)/W)*sizeof(int)/1024));\r
     R.tree = (int*) malloc (((R.n+W-1)/W)*sizeof(int));\r
     clearBit(R.tree,0); // clear all\r
     return R;\r
@@ -45,15 +45,13 @@ void freeResults (results R)
 static int conv (int p, int n, int lgn)\r
 \r
   { int t = n+1-(1<<lgn);\r
-    if (p < t) return p;\r
-    return (p<<1)-t;\r
+    return (p < t) ? p : (p<<1)-t;\r
   }\r
 \r
 static int unconv (int p, int n, int lgn)\r
 \r
   { int t = n+1-(1<<lgn);\r
-    if (p < t) return p;\r
-    return (p+t)>>1;\r
+    return (p < t) ? p : (p+t)>>1;\r
   }\r
 \r
 int readResult (results R, int p) // returns 0 or 1\r
@@ -184,9 +182,9 @@ static int nextLarger (int *tree, int n, int p, int pos, int pot)
 \r
   { int answ;\r
     if (!getBit(tree,pos)) return -1; // no answer\r
-    pot--;\r
     pos = (pos<<1)+1;\r
     if (pos >= n) return 0; // when n is not a power of 2, missing leaves\r
+    pot--;\r
     if ((p>>pot) == 0) // p goes left\r
        { answ = nextLarger(tree,n,p&~(1<<pot),pos,pot);\r
         if (answ != -1) return answ;\r
@@ -205,14 +203,13 @@ int nextResult (results R, int p) // returns pos of next(p) or -1 if none
   { int answ;\r
     if (((p+1)<<1) > R.n) return -1; // next(last), p+1 out of bounds\r
     answ = nextLarger(R.tree,R.n,conv(p+1,R.n,R.lgn),0,R.lgn);\r
-    if (answ == -1) return -1;\r
-    return unconv(answ,R.n,R.lgn);\r
+    return (answ == -1) ? -1 : unconv(answ,R.n,R.lgn);\r
   }\r
 \r
 // Naively implemented by kim\r
 \r
 unsigned int countResult(results R) {\r
-  unsigned int result = 0;\r
+  unsigned int result = -1;\r
   int i = 0;\r
   while ( i != -1 && i < R.n) {\r
     result ++; \r